Limit user access rights - MacOSX 10.5.6

I've got a few macbooks that will be used by my company during a show. The idea is that people will be able to use the macbooks to browse my company's website and register as our customers if they want. What I need to make sure is that they don't mess around with applications other than Safari (some kind of full screen mode where you need password to exit maybe?), and cannot browse other websites. So what I need is probably some sort of control software for macosx. Can I ask for everyone's suggestions. P.S. I'm not an advanced mac user, so I would prefer simple solution rather that using terminal and/or scripts. Thanks, Lukas